Pneumatic player mechanism for musical instruments



1,6 4,171 June 28, 1927. T. P. BROWN 3 PNEUMATIC PLAYER MECHANISM FORMUSICAL INSTRUMENTS Filed Sept. 5. 1923 4 sh nts-Sheet 1 12 Fla. 1.

INVENTOR. 77/60 fez ore P 57171072 ATTORNEY.

June 28, 1927;

T. P. BROWN ruzumuc PLAYER macamsm FOR MUSICAL ms'muusu'rs Filed Sept.5. 1923 4 Sheets-Sheet 2 an W 0/. mwm 0 0 3 E A TTORNEY.

1 192 June 7 r. P. BROWN PNEUMATIC PLAYER uncamsm FOR uusIcAp msmuusursFiled Sept. 5. 1923 4 Sheets-Sheet 3 mmvrm 77/9040)? P 57mm? BY J flATTORNEY.

June 28 1927.

Filed Sept. 5. 1923 4 Sheets-Sheet 4 ATTORNEY.

- Patented June 28, 1927.

UNITED, STATES PATENTSOFFICE.

THEODORE 1?. BROWN, OF-WORCESTER, MASSACHUSETTS, ASSIGNOR, BY MESNE .AS-

SIGNMENTS, TO SIMPLEX PLAYER AGTION 00., OF WORCESTER, MASSACHUSETTS.

PNEUMATIC PLAYER MECHANISM FOR MUSICAL INSTRUMENTS.

Applicati'on filed september 5, 1923. Serial No. 661,092.

My invention relates to pneumatic player mechanisms for musicalinstruments and has forits object to provide an improved .con-

struction of the bellows andpneumatic mechfl anism for actuating theplayer action, whereby the operation of the instrument is greatlyimproved. l

hen operating pneumatioplayer pianos of the type covered by the presentinvention,

it is of the utmost importance that the bellows device which controls.the operation of theIplayer action be adapted to readily respond to the.will of the operator, so as to; produce the great range of pressureintensities required in order to play the instrument with the properexpression. It has been found that when'the air reservoir or bellows iscompletely collapsed by the oper ation of the pump, thesuction producedbecomes very great, and that it is then very diflicult'for the-operator,to move the foot treadles which. operate thepump. Obviously, with such acondition, it; is impossible for the operator to produce the variationsof pressure so necessary for playinggwith expression, withoutexertingun'due effort in I movingthe foot, treadles. p Y According tothe presentinvention I provide an improved bellows device which is soconstructed that as the reservoir collapses, the resistance offered tothe movement of thefoottreadles by-the operator does not exhibitaanymarked increase, so that the operatoris able to maintainat all-times acomplete control over thepressure, without unduly exerting. himself. Myinvention further. contemplates .an improved construction of; the.pneumatic mechanism controlling the player action,-the individualpneumaticsbe- .ing constructedas uniits easily removed from theinstrument, and the entire pneumatic mechanism being adapted to bereadily removed from the pianowithout disturbing the adjustments ofthesame. The above and other advantageous features of my-invention .Wlllhereinafter more fully appear, reference being had to the accompanyingdrawings in which a "Fig. 1.,is 'a view, partially insection' andpartially in side-elevation, ofa player piano embodying my invention. Is

Fig. 2.-is.a view showing on an enlarged scale, thezbellowsdevice-shown. in Fig. 1, one of the feeders being in section.

Fig. 3 is a view in perspective of'the bellows device shown in Fig. 2.

Fig. 4c is a view, on an enlarged scale, of a. portion of the pneumaticmechanism shownin Fig. 1.

:Fig 5 is a perspective view of one of the pneumatic units shown in Fig.4.

Fig. 6 is a sectional view along the line of Fig. 5.

s Fig. 7 is a plan view of the diaphragm block of the pneumaticunitshown in Fig. 6.

Fig. 8 is an enlarged sectional viewof the valve of the unitshown inFig. 6.

Fig. 9 is a plan view of the guide for the valve, shown in 8.

Like referencev characters refer to like partsin the different figures.

Referring first to Figs. 1, 2 and 8, thebottoinboardof the pianoisindicated at 1 and carries a pair ofblocks 2 for supporting the air pumpand reservoir. The air'pump consists of a pair of feeders, each of whichcomprises a stationary leaf 3 and a movable leaf 4 connected by asuitable collapsible web 5, asbest shown in Fig. The movable leaf isnormally held in a collapsed position against the stationary lea-f. 3bymeans of a spring 6 .mounted on the outside of the feeder. The spring 6consists of oppositely curvedarms 7 ,which are adapted to engage lugsSprovided on theleaves 3 and 4 respectively, so'that the spring 6 isadapted to be readily removed from the feeder for the purpose ofadjusting or replacing the same.

The movable leaf 4 ofv each feeder is conlink 10, and thetreadles Q aremounted for pivotal movement on a cross barll. As.

best shown in Fig. 3, the cross bar 11- is U- shaped in form and itsends are plvotally ;mounted in sockets 12 carried by the blocks '2. Thecross bar 11 is adapted to be supported above the level of-the floor bymeans of downwardly extending-feetl which are adapted to be securedinposition on the bar 1]. by set screws'14. By means of the set screws 14,the feet.13 may be secured in different angular positions on the bar 11,so

as to compensate for variations in the distance between thebottom board1: of the piano and the floor on which the piano rests. lVhen the crossbar 11 is supported above the floor in front of the piano, as shown inFig. 1, it is obvious that the treadles 9 may be operated by footpressure to cause the movable leaves 1 of the feeders to be moved bacltand forth to exhaust; air from the col lapsible bellows. or reservoir,to which the feeders are connected. The reservoir consists of astationary leaf 15 and a movable leaf it; connected by a collapsible web17. The movable leaf 16 is normally held away from the stationary leaf15 by means of springs 18 carried at the ends of the reservoir. Eachspring 18 consists of divergent curved arms 19, the ends of which are inengagement with lugs :20 carried by the leaves 15 and 16 respectively,and the springs 18 may be readily removed from the reservoir foradjustment and replacement. The movable leaf 16 of the reservoir isformed of a number of separate laminations 16. so that the leafpossesses a certain amount of inherent resiliency, the advantage ofwhich will be hereinafter referred to with reference to the operation ofthe pump and reservoir. as will now be described.

hen the operator pushes down a treadle i), the corresponding feeder isexpanded due to the movement of the leaf 4, and the atmospheric pressureon the outside of the feeder serves to hold a valve 21 in position toclose the ports 22 in the leaf 4. The ere pansion of the feeder isadapted to exhaust: air from the reservoir through a port 23 and a valve2 1 which opens to suction. As soon as the operator releases a treadle9, the action of the corresponding feeder spring 6 re turns the movableleaf 4 to its collapsed position, whereupon the valve 21 opens torelease the air through the ports 22 while the valve 2-1- closes to lockthe suction created in the reservoir by the previous expansion of thefeeder. It is apparent then, that when the operator pushes first onetreadle 9 and then the other. the suction within the reservoir will beprogressively increased so as to cause the same to collapse againstthefo ce of the springs 18. The tension of the springs 18 is so adjusted,that the amount of suction required to initiate the movement of the leaf15 toward the leaf 16. is only sutlicient to operate the pneumaticaction of the piano so as to produce medium tone effects.

It has been found that with the type of reservoir heretofore employed,the amount of resistance encountered by the operator in moving thetreadles 9, remains about the same, until the reservoir is completelycollapsed. at which time the resistance to movement of the treadlesincreases very greatly, owing to the fact that the movable leaf 16 canmove no farther. It is also well known that when operating a playerpiano of the type to which my invention relates. the expression withwhich a piece is played, depends almost entirely upon the operation ofthe treadles 9. It therefore follows that when the resistance to themovement ot the treadles increases suddenly. following the a-essureintensities without oppof-iii'ig undut resist ance to the movement ofthe treadies one ating the feeders. To this end. T eoust :"i the movableleaf 16 of the reservoir of a number of laminations 16". and inaddition. provide a bumper project iug outwarll i from the face of thestationary leaf 1?. When the reservoir is partially collap ed byoperation of the pump, the uwvablc leaf 16 strikes the bumper thereb varresting the movement of the leaf 16. The creation of additionalsuction within the reservoir. after the leaf 16 has engaged the bumper'12:). causes the leaf 16 to yield toward the ea f 15, owing to itst'exible nature. The flexing of the leaf l6 permits a high pressure tobe built up and maintained without a sudden increase in the resistanceto movement of the treadles. as would follow if the leaf 16 wereentirely rigid and unyielding. i-Yith mv improved reservoir functioningas described. the operator can play the notes with a wide range ofpressure intensities. without ever encountering any great resistance tomovement of the treadles. as when us completely collapsible reservoirsof the t pc previously constructed. 7

Referring now to Figs. 1 and 1. the suction produced by the reservoir istransmitted through a tube 26 to the wind chest 52? by means of apassage 28 provided in the action block 29. A channel board 30 torusoneside of the wind chest 27 and has secured thereto two sets of pneumaticunits for op erating the player action. As previously set forth. myinvention contemplates an improved coustruction of the pneun'iaticunits. and as all these units are identical in construction, only onewill now be described in detail, withreference to Figs. 4: to 9inclusive. 7

Each pneumatic unit provides a chamber 31 which is connected to the windchest 27 through a channel 32 in the board 30. as shown in Fig. 6. Thetop of the chamber 3! is provided with an opening, the rim which issurrounded by a metallic annular valve seat 33, upon which is seated avalve member 34. As best shown in Fin. 8, the valve member 8 1 isprovided with a downwardly extending stem 34;. upon which closely tits ametallic guide 35. which as best till - valve, and at the same time,render it air tightwhen high pressures are developed, as willhereinafter be described.

The top of the valve 34 is covered'with a leather washer 38, which, whenthe valve 34 is'raiscd "from itslower seat, is adapted to engage anupper seat 39 having an opening 40'therein, as bestshown in Fig. '5. henthe valve '34 is in its lower position, as shown, the opening 40connects the'interior of the powerpneumatic 41 with the atn'iosphere, sothat the latter is maintained in. an expanded condition. T he movableleaf 42 of the power pneumatic provided with a finger 43 which, as bestshown'in Figs. 4 and 5, is cupped shape in form, witha slot extending'therethrough for receiving the pneumatic wire 4.4. Nuts45 are providedon the wire 44 for adjusting the same'on the finger 43, and the upperend of thewire 441s connect;

ed to a striking lever 46. The lever 46 is provided with a capstan orstud 47 which, as best shown inFig. 1, is adapted to engage the wippen48 of the piano action, which is illustrated as being of the usual form.A limit or stop, 49 is provided above the striking member 46 to limitupward movement of the. latter, so that the power pneumatic 41 will movethe wippen 4S exactly the same amount that it is moved by the key 50 ofthe piano when the pneumatic is actuated, will now be described.

A flexible diaphragm 51 divides the chamber 31 into two parts, and thatportion of the chamber below the diaphragm 51 is connect-- ed to avertical duct 52 in the channel board 30- by a horizontal passage 53.The diaphragm is normally maintained in the position shown by reason ofthe suction in the chamber 31 through the channel 32 and through thebleeder vent 57 extending from the duct 52, the valve 34 then beingtightly held against the seat 33 by atmospheric pressure on top of thevalve 34. The duct 52 is connected by a tube 54 to the tracker bar 55 ofthe piano, the opening at the end of the tube 54 being normally closedby the music sheet 56. lVhen, however, an opening in the sheet 56registers with the opening at the end of the tube 54, atmosphericpressure will be admitted through the duct 52 into the space below thediaphragm 51. This pressure will overcon'ie the suction through the vent57 and will cause the diaphragm 5,1 to be raised, thus lifting the valve34 away tromthe seatl-33tinto engagement with the upperseai 39.Theopening 40 is thus closed, and suction is exerted ontheinside ot thepower pneumatic 41, which causes it to collapse. The resulting upwardmovement of the leaf 42 is t 'ansmitted to the wippen 48 through thewire 44, andthe striking member 46, thus causing the note to be struck.As soon as the movement of the music sheet covers theopening in the tube54, the diaphragm 51 falls, the valve 34 closes, and the pneumatic 41 isagain expanded.

Each pneumatic unit is secured to the channel board 30 by means ofscrews 58, and inerder to remove a unit from the pianoit is onlynecessary to remove the screws 58 and to slip the wire 44 out o'f theslot in the cupped-shape finger 43. The units are interchangeable, andbeing aranged in only two tiers, occupy a minimum amount of spacehepiano. Forthis reason thedia- 51, together with its float 51 is al inform, asshown in'Fig. 7, thus materially reducing the width of myimproved unit as COHIPLH'GCllZO previous unit einployinga circulardiaphragm. prc ously pointed out, the valve 34 of eachpneumatic unit isadapted to seat very tightly on tlie annular valve seat 33 by reason ofthe fact that the rim of the seat 33 engages the unglued portion of thecov'ei"='36.

lhe/l actthat there is always a very-small clearance between the ungluedportion of the cover 36 and the washer 37 insures that when the valve 34is seated by suction in the chamber 31, the layers of leather willcompress slightly and provide a substantially air tight closure for thechamber. Obviously, the greater the suction to which the valve issubjected, the more tightly it will be seated, so that the type of valvedescribed herein particularly adapted for use in con nection with myimproved air reservoir. As previously pointed out, the provision of theflexible leaf 16 in my reservoir permits a strong suction to be createdWithout the exertion of undue effort on the part of the operator to movethe foot treadles, and in order that the suction be maintained, it ismost essential that the valves in the pneumatic units be air tight. Byusing a tight seating valve in connection with a suction creating devicewhich can be operated without undue ellort, I am able to employ andmaintain extremely high pressures for operating the penumatic playeraction. As a result, the pneumatic units can be reduced in size ascompared to those previously employed, which permits the very compactarrangement of the pneumatics in two tiers. For the same reasons, theproportions of the entire pumping device can be reduced, which resultsin a smaller and more compact arraugen'rent of the entire instrument.

From the foregoing then, it is apparent that by my invention I haveprovided an improved suction creating mechanism that is particularlyadapted for use in connection with an improved form of pneumatic unit,whereby the playing qualities of the instrument are bettered and itsease of ope 'ation greatly increased.

I claim:

1. In a player for musical instruments, the combination with a valvemechanism for controlling a pneumatic player action, and a suctioncreating crevice, of a collapsible reservoir adapted to be exhausted bythe operation of said suction creating device, said reservoir comprisinga substantially rigid leaf and a movable leaf of material having markedresiliency as compared to said rigid leaf.

2. In a player for musical instruments a collapsible air reservoircomprising a substantially rigid leaf, a movable leaf of materialhavinn' marked resiliency as compared to said rigid leaf, and means forpartially limiting the movement of said resilient leaf in the directionof said rigid leaf when the reservoir has collapsed a predeterminedamount.

3. In a player for musical instruments, at collapsible air reservoircomprising a substantially rigid leaf, a movable leaf of material havingmarked resiliency as compared to said rigid leaf, and a stop forlimiting the movement of a portion of said resilient leaf when thereservoir has collapsed a predetermined amount. whereupon the remainderof said resilient leaf is adapted to yield in the direction of saidrigid leaf.

4. In a player for musical instruments, a collapsible air reservoircomprising a sub stantially rigid leaf, a movable leaf of materialhaving marked resiliency as compared to said rigid leaf, a spring forholding said leaves apart, and means for partially arresting themovementof said resilient leaf after it has moved a predetermined amountagainst the force of said spring, whereupon the said movable leafadapted to yield further by reason of its resilient nature.

5. In a player for musical instruments, the combination with a valvemechanism for controlling a pneumatic player action, a suction creatingdevice, of a collapsible reservoir adapted to be exhausted by theoperation of said device, said reservoir comprising a substantiallyrigid leaf, a movable leaf of material having marked resiliency ascompared to said rigid leaf, and means for partially limiting themovement of said re sili-ent leaf after said reservoir has beencollapsed a predetermined amount by said enction creating device,whereupon said movable leaf is adapted to yield toward said rigid leafin response to further operations of said suction creating device. i

THEODORE P. lilltm i

